When President Trump argues that the United States can’t halt arms sales to Saudi Arabia over the Saudis’ alleged murder of journalist and Post contributor Jamal Khashoggi, he’s giving up a key piece of leverage over Riyadh for no reason at all. What’s worse, Trump is also turning one of America’s best strategic assets into a liability, a massive unforced error that could weaken the United States worldwide.

Trump has said repeatedly he doesn’t want to halt — or even threaten to halt — U.S. arms sales to the Saudi regime because (he says) it would cost U.S. jobs and hand over a sweet contract to Moscow or Beijing.

“They are ordering military equipment. Everybody in the world wanted that order. Russia wanted it, China wanted it, we wanted it. We got it,” Trump said on “60 Minutes” Sunday. “I don’t want to hurt jobs. I don’t want to lose an order like that.”

Set aside that Trump’s claim of $110 billion of arms sales to Saudi Arabia as announced last year is hugely exaggerated, considering that number mostly refers to deals struck during the Obama administration and new deals that haven’t yet materialized. The significant arms-sales relationship we do have with Saudi Arabia gives us enormous leverage over them, leverage Trump should use to pressure King Salman to reveal what his regime knows about Khashoggi’s disappearance.

Saudi Arabia’s military is already built around U.S. and British defense platforms, meaning they can’t easily switch to Russian or Chinese systems. Riyadh is especially dependent on U.S. arms right now because their bloody war in Yemen requires a constant flow of U.S. munitions, not to mention U.S. intelligence, maintenance and refueling support.

U.S. arms sales are not simply a financial deal or a jobs program; they represent a strategic advantage of the United States. Countries want U.S. weapons because they are the best. That gives us connections, influence and, yes, leverage over these countries. That’s how arms sales have always worked, until Trump flipped the script.

“The White House seems to be saying that Trump Doctrine is that the U.S. will ignore your human rights abuses, assassinations or war crimes as long as you buy things from us. He’s got it totally and completely backwards,” Sen. Chris Murphy (D-Conn.) told me. “What’s the point of being a military superpower if we lose leverage when we do business with another country?”

“What the president doesn’t realize is that this makes him look weak and small. World leaders will now know they can act with impunity so long as they are buying American weapons. That’s an insane message to send,” Murphy said. “The United States should never be boxed in because of who we sell weapons to — countries who buy U.S. weapons should feel enormous pressure to stay on our good side.”

“Arm sales are important, not because of the money, but because it also provides leverage over their future behavior,” he said. “You know … they will need our spare parts. They will need our training. And those are things we can use to influence their behavior.”

Congress does have a role to play in approving arms sales, and all indications are that they plan to intervene on sales to Riyadh if it is shown that the Saudi regime had a hand in Khashoggi’s death. The State Department approved a $15 billion sale of the Terminal High Altitude Air Defense (THAAD) missile defense system to Saudi Arabia this month. The Pentagon said last week Saudi Arabia has signed letters of offer or acceptance of $14.5 billion worth of American helicopters, tanks, ships, weapons and training.

In June, the Senate narrowly voted down a resolution to halt the sale of hundreds of millions of dollars worth of precision-guided munitions to the Saudi military out of concern they could be used to target Yemeni civilians. After the vote, Senate Foreign Relations Committee ranking Democrat Robert Menendez (D-N.J.) said he opposed the sale, placing it in limbo.

The threat of congressional action would be more effective if the president of the United States wasn’t publicly undermining Congress’s message, said William Hartung, director of the Arms and Security Project at the Center for International Policy.

“Trump is not even trying to use this leverage,” he said. “He’s completely given it away, and not only that, he’s announced to the world that he’s giving it away.”

Through a basic misunderstanding of national security and diplomacy, the president has once again undermined U.S. interests and made the work of his own team — including Secretary of State Mike Pompeo — much more difficult. Thinking of arms sales purely in dollar terms doesn’t make any sense.

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Josh RoginJosh Rogin is a columnist for the Global Opinions section of The Washington Post. He writes about foreign policy and national security. Rogin is also a political analyst for CNN. He previously worked for Bloomberg View, the Daily Beast, Foreign Policy, Congressional Quarterly, Federal Computer Week and Japan's Asahi Shimbun newspaper. Follow